Objective To explore the clinical results of minimally invasive therapy for femoral intertrochanteric fractures with proximal femoral nail anti-rotation(PFNA) in 25 elderly patients.Methods A total of 25 patients with intertrochanteric fractures were treated by PFNA in our hospital from February 2007 to June 2008.The patients received close reduction and minimal invasive operation.Based upon the Tronzo-Evans classification,type Ⅰ fractures were diagnosed in 2 cases,type Ⅱ fractures in 2 cases,type Ⅲ in 16,and type Ⅳ in 5.Results The mean operation time in this series was 50.3 min(30-70 min),an the mean intraoperative blood loss was 100.2 ml(70-200 ml).All the 25 patients completed a follow-up of 3 to 12 months(average time 7.1 months),during which all the fractures healed in 10 to 14 weeks with a mean of 11 weeks,without occurrence of varus deformity,hardware loosening or hardware cutting.According to the Harris Hip Score,20 cases achieved excellent results,4 were good,and 1 was fair. Conclusions It is a reliable and ideal method to treat intertrochanteric fractures with PFNA in elderly patients,for the procedure is convenient and minimally invasive,resulting in firm fixation,less blood loss,short operation time,and high healing rate.

Objetive To investigate physicians'knowledge regarding intravenous fibrinolytic therapy for acute ischemic stroke and whether their hospitals could meet the requirements for the therapy. Methods Questionnaires were mailed to 500 physicians from 153 hospitals in Shanxi including 112 secondary and 41 tertiary hospitals. 370 physicians returned valid questionnaires. Results One hundred thirty-four hospitals (87.6%) could provide 24-hour computed to?mography service, including 95 (84.8%) secondary hospitals and 39 (95.1%) tertiary hospitals. Alteplase stock was avail?able in 59 hospitals (38.6%), containing 25 (22.3%) secondary and 34 (82.9%) tertiary hospitals. Accuracy rates of 13 questions regarding intravenous fibrinolytic therapy for acute ischemic stroke ranged from 30.8% to 82.9%. Accuracy rates of 6 questions were lower than 50.0%. Conclusions The present study has revealed that physicians in this study have poor knowledge regarding the therapy. The situation can not meet the demand of healthcare, which partially ac?counts for the low rate in fibrinolytic therapy in Shanxi. Relevant training and suitable assessment should be carried out compulsively to ensure that physicians grasp necessary knowledge and skills.

Objective To investigate the mid-term efficacy and complications of bone cement or biotype hemiarthroplasty for the femoral neck fracture in the elderly patients.Methods From January 2011 to January 2014,sixty-seven elderly patients (67 hips) with femoral neck fracture were treated with hemiarthroplasty.All patients were treated with bipolar femoral head prosthesis,and the prosthesis included into bone cement and biologic type,according to the fixation of the femoral stem.The 3 year postoperative Harris score and surgeryrelated complications (joint dislocation,prosthesis loosening,acetabular subsidence,and mortality) were evaluated.Results All patients were followed up for 3 years.The excellent and good rate of Harris score was 87.1％ (27/31) in the bone cement group and 80.6％ (25/31) in the cementless group (X2 =0.47,P＞0.05).There was no significant difference in the complications between the two groups (P＞0.05).Conclusion The hemiarthroplasty is an effective and safe methodfor the treatment of femoral neck fracture in the elderly.The key to achieve excellent results is to choose the femoral prosthesis based on the preoperative planning and operation.

Objective To clarify the characteristics of shock wave sources generated at different medium interfaces.Methods The experiment used an in vitro adjustable impact pressure shock wave generation and signal acquisition system combined with a flexible PVDF sensor.The waveform of the shock wave generated by the applicator at the interface of different media(soft tissue-mimicking phantom,water and air)was explored.The characteristics of the shock wave source in the time and frequency domains were analyzed.Results When the same impact pressure was applied,shock waveforms generated at the interfaces of the phantom and water exhibited similar characteristics from a time-domain perspective.At the same time,both differed significantly from those generated at the air interface,where the absolute values of the positive and negative pressures were noticeably reduced.The characteristics of the shockwave spectra in various media revealed three distinct peak frequencies,with the modulation frequencies varying in the phantom(12.2 kHz),water(8.5 kHz),and air(7.2 kHz).In contrast,the carrier frequency remained relatively constant(between 82 and 83 kHz).When different impact pressures were applied,there was little influence on the waveform at the same medium interface,indicating that the impact pressure affected only the shockwave amplitude and not the peak frequency.As the impact pressure increases,the absolute values of the positive and negative pressures at the medium interface increase linearly.Conclusions Shockwave sources can be effectively measured using a flexible PVDF sensor.Shock waves generated at different medium interfaces exhibit temporal and spectral differences,indicating that the characteristics of shock wave propagation in air or water cannot be substituted for those in biological soft tissues.These findings provide crucial information for evaluating shockwave devices and formulating treatment protocols in the clinic.